Improvement in bit-stocks



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DANA P. FOSTER, 0F WALTHAM, MASSACHUSETTS.

ALetters Patent No. 101,251, dated March 29, 1870.

IMPROVEMENT IN BIT-STOCKS.

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The Schedule referred to in these Letters Patent and making part of the same To'all whom it may concern Be it known um I, DAN P. Fos'inn, of Waltham, in the county of Middlesex and State of' Massachusetts, have invented certain new and useful Improvements in Bit-Stocks; and I do hereby declare that the following is a full and exact description thereof, reference being had to the accompanying drawings and to the letters of reference marked thereon.

The nature of my invention consists in arranging within the bit-socket a self-adjusting washer in such la manner that the shank of the bit will have more than one support, although it may not have been fitted expressly to this bit-stock; in other words, differently beveled Shanks will beheld steadily by my device.

It also consists in the method of attaching the headpiece.

To enable others skilled in the art to make and use my invention, I will proceed to describe its construction and use.

v Drawings..

Figure 1 is an elevation of the hit-stock.

` Figure 2 is a section ofthe same.

Figure 3 is an enlarged scctionshowing the construction of' theliead piece,

bles H and H screw, are made slightly conical, and

the tubes themselves slotted or cut 1ongitndinally,so that by screwingr up H and H' the caliber will be slightly lessened.

The two ends C and'l) of the crank-part Flare bent,

as shown in figs. 1 and 2, and slide .into the hollow parts E and B, as shown, fitting loosely when the screws H and H are but partially screwed on, but when the thimbles H and H are screwed entirely on, they diminish the caliber of B and D sufficiently to hold 'C and E firmly.

O, figs. I and 4, represent a screw-thimble, which has an opening, Q, in its end, and an opening, V, on the side, so that when it is screwed out, as represented in fig. 4, the shank of the bi't may beeasiiy entered into the openings'c and b, figs. 4 and 5. YVhen the bit is tlms entered the thimble may be screwed up so as to firmly hold it.

N', figs. 4 and 5, is a movable washer, having an orifice, l), somewhat smaller than the orifice o, so that, when the tapering shank of the bit is placed in position, as represented by dotted lines in fig. 5, the washer Nwill-yield suiciently to allow the shank to tit itself to bothl orifices, c and b, and thus to be held true and firmly.

-P is a spring acting against the washer N', to keep it in position.

A represents the head piece, and is connected to the upper end of the tube B by means of the bolt I and hollow screw-plug K, shown in fig. 3.

The bolt I has a head, I', and is free to revolve in K.

L is a cup-shaped washer, which serves a double purpose; rst, it forms a part of and strengthens the head; second, it acts-as a check-nut to hold the head iirmly to the bolt I.

M is a screw-nut inserted iu the wood-part A, which may be dispensed with in case A is made of metal.

In the drawing,fig. 3, L is shown atalittle distance above K, but when in use L rests upon K.

For convenience in removing the head, an oritice, a, is made in the tube B, and a corresponding orifice, a', is made in the head1" of the holt I, so that by inserting a pin, the boltI will be prevented from revolving,

Ain which case the head may be easily unscrewed.

2. The arrangement of the bolt I, the cup-shaped4 washer L,'the screw-plug K and head A, constructed as shown and described, and for the purpose set forth.

D. P. FOSTER.

Witnesses: Jas. L. CONANT,

FRANK G. PARKER. 

